Overlap cooperative spectrum sensing with energy comparing in cognitive radio networks

In cognitive radio network, cooperation multiple secondary users can improve the performance of spectrum sensing. However, the sensing process duration is generally increasing because the number of the local decisions needing to be sent to the fusion center. Most alternative works consider a general time frame structure in which all the cognitive radio users (CRs) sense the signal in the same time and then each user must waits for its turn to report its observation. Hence, there is a waste of the time here and this time consumed by waiting can contribute little to the performance of spectrum sensing. In this paper, we propose an overlap spectrum sensing, the CRs keep collecting and fusing the signal while another is reporting to FC. By making use of the waiting time for sensing, the new framework provides a much wider observing window for spectrum measurement, which results in a performance improvement of spectrum sensing. Besides, we also apply the energy comparing to choose the good CR to send its local decision in each reporting time slot. The sensing performances of this sensing strategy are analyzed and confirmed by the Monte-Carlo simulation results.